Trinitite. Nuclearon specializes in trinitite and other interesting radioactive artifacts and objects. They donated this lovely sample of green glass trinitite, remnants of the Trinity test, the first nuclear explosion created by the hand of man. More details about the origin and characteristics of trinitite can be found at this page about the varieties of trinitite.
Interestingly, I got this sample right around the time I exchanged some email with Ellen Klages, the author of The Green Glass Sea, a children's book about the trinity test. The title of the book certainly evokes the nature of this amazing material.Source:NuclearonContributor:NuclearonAcquired:13 June, 2008Text Updated:14 June, 2008Price: DonatedSize: 1"Composition:SiO2